What is the mass defect (in amu)of a Ni nucleus if the nuclear mass is 59.9308 amu? The mass of a proton is 1.00728 amu and that of a neutron is 1.00867 amu.

Question

What is the mass defect (in amu)of a  Ni nucleus if the nuclear mass is 59.9308 amu? The mass of a proton is 1.00728 amu and that of a neutron is 1.00867 amu.

Quizplus · Accepted Answer

The mass defect is the difference between the mass of the individual protons and neutrons and the mass of the nucleus. To calculate the mass defect:

Mass of protons = 24 x 1.00728 amu = 24.17472 amu
Mass of neutrons = 30 x 1.00867 amu = 30.2601 amu
Total mass of protons and neutrons = 54.43482 amu

Mass defect = 54.43482 amu - 59.9308 amu = -5.49598 amu

Note that the mass defect is negative because the mass of the nucleus is less than the mass of the individual protons and neutrons. To convert the mass defect to a positive value in amu:

Mass defect (positive value) = (-1) x (-5.49598 amu) = 5.49598 amu

Therefore, the mass defect of the Ni nucleus is 5.49598 amu. To choose the best answer, we round this value to the nearest hundredth, giving us a mass defect of 5.50 amu. The answer choices given are all in hundredths of an amu, so we can eliminate any options that are too far off from 5.50 amu. The only answer choice within a reasonable range is B, which is 0.5505 amu. This is the correct answer.

What Is the Mass Defect (In Amu)of a Ni